Minimally ablative resurfacing with the confluent 2,790 nm erbium:YSGG laser: a pilot study on safety and efficacy.

BACKGROUND: The 2,790 nm Er:YSGG wavelength has a lower water absorption coefficient than the 2,940 nm Er:YAG, but a higher coefficient than the 10,600 nm CO(2) laser. This allows ablative resurfacing with mild thermal coagulation, which may increase clinical efficacy while reducing patient downtime. OBJECTIVES: To evaluate the efficacy and safety of the confluent 2,790 nm Erbium:YSGG (Pearl™, Cutera) laser for facial rejuvenation. STUDY DESIGN/MATERIALS AND METHODS: Eleven subjects (mean age 50, skin types I-III) with mild to moderate photodamage and wrinkles had two facial treatments with the 2,790 nm Er:YSGG laser using a fluence of 3.5 J/cm(2), pulse duration of 0.4 msecond, and 20% overlap. Treatments were performed 6 weeks apart. Pre-auricular biopsies from five subjects were evaluated at baseline and 6 weeks after the final treatment. Data from blinded photo assessments and subjects' self-assessment of improvement were analyzed 6 weeks after the final treatment. Additionally, long-term safety and efficacy were evaluated 2 years after the final treatment. RESULTS: Histologically, 80% of subjects had new collagen formation in the dermal grenz zone, and 60% had increased epidermal thickness. Almost all subjects (91%) showed improvement in tone/texture, 82% of subjects showed improvement in dyschromia and fine lines, and 54% showed improvement in wrinkles 6 weeks after the final treatment. Subjects' self assessment indicated "significant" to "dramatic" improvement in dyschromia (91% of subjects) and tone/texture (82%) 6 weeks after the final treatment. All subjects saw "mild" to "significant" improvement in fine lines and wrinkles. At the 2-year follow-up visit, 57% of the overall improvement achieved at 6 weeks was maintained. No adverse events were reported throughout the study. CONCLUSION: Ablative resurfacing with the 2,790 nm Er:YSGG laser demonstrated visible improvement in photodamage with good tolerability and minimal downtime. Subjects were highly satisfied, especially with respect to dyschromia, skin tone, and texture.

Survey of regional laser centers: a Minnesota perspective.

BACKGROUND: Laser use in medicine is rapidly expanding as patients seek treatment for medical and cosmetic purposes. Concern is mounting about the unsupervised use of lasers and similar devices by nonphysician personnel. Minnesota is currently one of the few states with no legislation regarding the uses of lasers. OBJECTIVE: To determine whether laser centers in Minnesota meet professional standards and guidelines for patient safety. METHODS AND MATERIALS: Public resources were used to identify all businesses with laser services in Minnesota cities with a population of at least 1,000 people. Each laser center was contacted, and a "secret shopper," a person who posed as a potential patient administered a telephone survey. RESULTS: A wide range of physicians and nonphysician personnel offer laser services in Minnesota. Supervision was not standardized and varied widely across the laser centers. CONCLUSIONS: As the demand for laser services increases, the use of lasers must be clearly defined and regulated to prevent patient injury. The authors have indicated no significant interest with commercial supporters.

Histologic analysis of a 2,940 nm fractional device.

BACKGROUND AND OBJECTIVES: An evaluation of the histological effects of a 2,940 nm fractional erbium:YAG (Er:YAG) laser device with adjustable depth and coagulation settings in a human abdominoplasty model. The goal of this study was to use light and confocal microscopy to determine the dimensions of the microthermal zones (MTZs) created by this device in the epidermal and dermal layers. STUDY DESIGN/MATERIALS AND METHODS: Three subjects were consented and treated after being randomly assigned to a laser depth of either 250 µm, 500 µm, or 1,000 µm. Four coagulation levels were tested in each subject. Two biopsies were taken immediately, 1 and 2 weeks post-treatment from each zone and viewed by light and confocal microscopy. Two blinded observers examined the sections for changes in collagen and measured depth and width of the MTZs. Coagulation was assessed and recorded as the depth and width of denaturation; measured as the depth and width of ablation plus surrounding thickness of thermal necrosis from dissipated heat. RESULTS: Light microscopy findings in all treated samples showed a perforated epidermis and dermis immediately after treatment. The depths of ablation produced did not accurately reflect the three different laser settings. Depths of denaturation also did not increase with increased coagulation level settings as expected. The width of ablation in the MTZs, a non-adjustable setting, was the most accurate and reproducible in all subjects. Confocal microscopy samples revealed the presence of collagen remodeling in the dermis, which increased significantly at 1 and 2 weeks post-treatment. CONCLUSIONS: Treatment with the 2,940 nm Er:YAG device led to significant changes of the dermis at light microscopy levels. The adjustable laser depth and coagulation settings did not produce predictable depths of ablation or denaturation, possibly as a result of the variation of tissue hydration properties among individuals. Increased collagen remodeling was seen in the dermis in all subjects at 1 and 2 weeks post-treatment.

Evaluation of a fractional laser with optical compression pins.

BACKGROUND AND OBJECTIVE: Non-ablative fractional lasers have been used in skin rejuvenation procedures with some success. In general, the optimum area coverage and depths of the fractional thermal injury zones depend on the specific indications of interest. For all fractional devices, depth is adjusted with energy that also determines the coagulation area at the dermal/epidermal junction. Micro-beams (µB) of a 1,540 nm laser are co-aligned with optical pins in a device designed to provide skin compression during treatment to remodel the deeper reticular dermis and hypodermis while minimizing epidermal damage. The device is characterized in ex vivo and clinical studies. MATERIALS AND METHODS: Ex vivo porcine skin was treated with a compression-pins optic connected to an Er:Glass laser hand piece. Nitroblue tetrazolium chloride (NBTC) cell viability staining of horizontal radial and vertical sections of post-treatment skin was used to assess coagulation profiles. A pilot clinical study was also performed to evaluate the effects of compression on epidermal injury. RESULTS: The compression-pins optic provided deeper coagulation to 1.5 mm depths and less epidermal injury than without compression. Coagulation depth was increased further with stacked pulses. CONCLUSION: The ability to de-couple depth of treatment from area coverage provides greater flexibility of treatments. The results promise greater possibilities to vary dermal injury patters which may offer increased benefit in treating a variety of cutaneous conditions.

Clinical study to determine the safety and efficacy of a low-energy, pulsed light device for home use hair removal.

BACKGROUND AND OBJECTIVES: The principle of selective photo-thermolysis has been studied extensively for hair removal applications in a medical setting. A new, portable, hand-held device featuring two filtered Xenon lamps that utilizes pulsed light in low optical fluencies for hair removal has been developed for consumer use. The purpose of this clinical study was to determine the efficacy and safety of this low-energy, pulsed-intense light device intended for home use hair removal. STUDY DESIGN/ MATERIALS AND METHODS: The treatment group consisted of 10 adults with skin types I-IV who possessed unwanted dark hair in the non-facial region. The subjects received between 4 and 6 treatments on a bi-weekly basis with the device by a trained member of the clinical staff. The clinical responses were evaluated by performing manual hair counts using magnified vision and photographs which were obtained prior to treatment and at each subsequent visit. RESULTS: Mean hair reduction was 36% 4 weeks after the final treatment and 10% 12 weeks after the final treatment. This resulted in a mean hair count reduction of 23% over the two follow-up appointments. There was no definitive correlation between customer satisfaction and hair count reduction. Adverse reactions were limited to transient, localized, post-treatment erythema. No complications were encountered. CONCLUSIONS: This low-energy, pulsed-light device is a quick, safe, and relatively effective at-home hair reduction treatment option in patients with various skin phototypes.

Semi-Automated method of analysis of horizontal histological sections of skin for objective evaluation of fractional devices.

BACKGROUND AND OBJECTIVE: The treatment of skin with fractional devices creates columns of micro-ablation or micro-denaturation depending on the device. Since the geometric profiles of thermal damage depend on the treatment parameters or physical properties of the treated tissue, the size of these columns may vary from a few microns to a few millimeters. For objective evaluation of the damage profiles generated by fractional devices, this report describes an innovative and efficient method of processing and evaluating horizontal sections of skin using a novel software program. MATERIALS AND METHODS: Ex vivo porcine skin was treated with the Lux1540/10, Lux1540 Zoom and Lux2940 with 500 optics. Horizontal (radial) sections of biopsies were obtained and processed with H&E and NBTC staining. Digital images of the histologic sections were taken in either transmission or reflection illumination and were processed using the SAFHIR program. RESULTS: NBTC- and H&E-stained horizontal sections of ex vivo skin treated with ablative and non-ablative fractional devices were obtained. Geometric parameters, such as depth, diameter, and width of the coagulated layer (if applicable), and micro-columns of thermal damage, were evaluated using the SAFHIR software. The feasibility of objective comparison of the performance of two different fractional devices was demonstrated. CONCLUSION: The proposed methodology provides a comprehensive, objective, and efficient approach for the comparison of various fractional devices. Correlation of device settings with the objective dimensions of post-treatment damage profiles serve as a powerful tool for the prediction and modulation of clinical response.

Evaluation of a novel fractional resurfacing device for treatment of acne scarring.

BACKGROUND AND OBJECTIVE: Pulsed carbon dioxide (CO(2)) laser devices are considered highly effective treatment options for skin resurfacing. However, the high risk for significant treatment complications following CO(2) resurfacing has warranted the development of new treatment modalities. The concept of fractional photothermolysis was developed to address the shortcomings of ablative and non-ablative device modalities. This report evaluates a fractional approach to CO(2) laser resurfacing for the treatment of moderate to severe acne scarring. The primary endpoint of the study was the overall improvement in the appearance of acne scarring. STUDY DESIGN/MATERIALS AND METHODS: Thirty subjects, with moderate to severe acne scarring, underwent up to three treatments with an FDA IDE and IRB approved 10,600 nm fractional CO(2) laser system. All subjects were Fitzpatrick skin types I-V and 18-75 years of age. Treatment parameters ranged from 20 to 100 mJ with total densities of 600-1,600 MTZ/cm(2). Improvement of acne scarring was evaluated at 1 and 3 months post-treatment. RESULTS: Twenty-three out of 25 subjects sustained clinical improvement in the appearance of acne scarring at the 3-month follow-up visits according to study investigator quartile improvement scoring. Subjects also had improvement in their overall appearance, including pigmentation and rhytides. Serosanguinous oozing resolved within 24-48 hours following treatment. All subjects had transient erythema, which resolved in the majority of subjects within 1-3 months. Post-operative downtime was significantly decreased compared to traditional ablative resurfacing. No serious complications were reported. CONCLUSION: Fractional deep dermal ablation improves moderate to severe acne scarring. The added benefit is a considerable reduction both in downtime and risk of complications when compared to traditional CO(2) ablative resurfacing techniques.

Pilot investigation of the correlation between histological and clinical effects of infrared fractional resurfacing lasers.

METHODS: Yucatan Black pig skin was treated with a 1,540-nm erbium (Er):glass laser (Lux1540, 15 and 30 mJ) and two 1,550-nm Er-doped fiber lasers (Fraxel SR750 and SR1500, 8, 10, and 12 mJ). Histologic sections were examined to determine the depth of damage and to correlate subjects' clinical response. Concurrently, six subjects with photodamaged skin received three split-face and ipsilateral dorsal hand treatments with the 1,540-nm Er:glass laser on one side and one of the 1,550-nm Er-doped lasers (Fraxel SR750) on the other. RESULTS: The 1,550-nm Er-doped lasers, using lower fluences and higher densities, produced shallower micro-columns than the 1,540-nm Er:glass device at higher fluences and lower densities (mean depths 250-275 microm vs 425-525 microm, respectively). Blinded assessors found greater overall improvement in pigmentation with the 1,550-nm Er-doped laser and better overall improvement in texture with the 1,540-nm Er:glass laser. CONCLUSIONS: Greater densities of shallower damage columns at lower energies may better improve pigmentation, whereas deeper injuries, using higher energies and moderate densities, may better improve texture. This pilot study did not compare similar fluences and histologic damage between the two systems, and newer available systems allow for greater depth of penetration.

Allergic contact dermatitis from propolis.

Propolis is commonly used in cosmetic and medicinal preparations because of its antiseptic, antiinflammatory, and anesthetic properties. Its therapeutic qualities have been well documented. However, 1.2 to 6.6% of patients who are patch-tested for dermatitis are sensitive to propolis. The main allergens are 3-methyl-2-butenyl caffeate and phenylethyl caffeate. Benzyl salicylate and benzyl cinnamate are less frequent sensitizers. Propolis is found in a number of "natural" products, including lip balms, cosmetics, lotions and ointments, shampoos, conditioners, and toothpastes. Dermatologists should consider patch testing with propolis in users of such remedies.